the 4-5th fully expanded leaves from the top of the chrysanthemum were selected at 0,15,30,45,60 DAS (day after treatment)
the leaves were soaked in 80% acetone for 12-24h and then centrifuged at 5000 rpm for 10 min.
the supernatant was collected.
then the absorbency of the supernatant was read at 645 and 663nm, respectively.
the content of chlorophyll was calculated according to the equation: 20.2a663+8.02a663